The identity of the mysterious rat killer was seemingly revealed in last night’s episode “Inmates” as promised by The Walking Dead showrunner Scott Gimple.

“We will absolutely find out more about the rats and the person who seemed to dissect that rabbit that Tyreese (Chad Coleman) found in the tombs before the Governor showed up,” Gimple told Hollywood Reporter about the second half of the season.

All the clues point to Lizzie (Brighton Sharbino), who is extremely cold throughout the episode. She callously tells her sister Mika (Kyla Kenedy) to get over the absence of their adoptive mother Carol. Lizzie tells her that she’s lucky she’s not missing like Sasha implying that she’s dead. Lizzie kills rabbits for her own enjoyment while sitting around a campfire. She hides the bodies indicating that she knows what she’s doing is wrong. The next morning, Daryl (Norman Reedus) and Beth (Emily Kinney) search the area but don’t see the dead rabbits stuffed in a tree log.

Tyreese (Chad Coleman) leaves the girls to help another group of survivors. He gives Judith to Lizzie and his gun to Mika then tells them to stand back to back so they can see approaching walkers. The baby starts crying and Mika pleads for her sister to make her stop so Lizzie smothers Judith to keep her quiet. The scene is reminiscent of the M*A*S*H finale, in which a North Korean refugee smothers her baby to avoid detection. The difference is that Lizzie has no compunction about killing the baby. In fact, she seems to be enjoying it.

Her behavior is similar to that of the comic book character Ben, a disturbed child who kills a cat and then his twin brother Billy in The Walking Dead #61.

Ben was ultimately put down by Carl because no one else was willing to do it. Rick concealed what his son did from the rest of the group including Ben’s adoptive parents Dale and Andrea.

Assuming that creator Robert Kirkman wants to keep the story close to the comic, which is admittedly a big assumption, we could see Lizzie kill Mika. However, I can easily see Kirkman reversing this dynamic for some post-mortem justice. Tyreese has been encouraging Mika to be strong as demonstrated by him giving her the gun. Perhaps Mika will be the one to kill her deranged sister. It would be a rare pseudo-happy ending similar to the survival of baby Judith, who died with her mother in the comic.

UPDATE:

Sadly, the show stays true to the comics and Lizzie kills Mika but this time it’s Carol who puts her down.